30C-33 |
Effect of exogenous ascorbyl palmitate and alpha-tocopherol on fresh beef packaged under modified atmospheres. I. Color stability and lipid oxidation. |
C. R. A. SOUZA and M. N. Oliveira. Depto. Tecnologia Bioquímico-Farmacêutica, Universidade de São Paulo, Av. Prof. Lineu Prestes, n.580, bl. 16., São Paulo, 05508-900, Brazil Modified atmosphere packaging (MAP) is widely used to store chilled beef. While high oxygen levels are known to prolong color stability, it is also expected that the rate of lipid oxidation will increase. The use of ascorbyl palmitate and alpha-tocopherol delays oxymyoglobin and lipid oxidation and prolongs the color stability of beef. The results can vary depending on concentrations of the antioxidants. Our objective was to study the effect of ascorbyl palmitate (X1) and alpha-tocopherol (X2) dip treatment on color and rancidity characteristics of fresh beef in modified atmosphere packs. Fresh beef steak samples were dipped into antioxidant solutions; packed under MAP with different levels of O2, CO2, and N2; and stored at 4ºC for 10 days. Meat samples were analyzed during storage for surface color and extent of lipid oxidation (TBARS). An experimental design (DCC) with 8 factorial points and 6 central points was used to develop response surface models for predicting the combined effects of X1 and X2 concentrations in the dip solution. The concentrations of X1 and X2 varied from 0.15 to 0.85% and from 0.02 to 0.14% (p/v), respectively. The validity of the models was assessed using ANOVA (p £ 0.05). Response surface plots displaying the levels a* and TBARS, when varying the antioxidants concentrations, were used for final interpretation. In order to maintain a good meat color and also low levels of TBARS, optimal concentrations below 0.38% p/v of ascorbyl palmitate and between 0.09 to 0.11% p/v of alpha-tocoferol in the dip solution were established by models for all atmospheres. A significant interaction (p £ 0.05) between these antioxidants was found. Response surface models are able to show the best concentrations of antioxidants in the dip solution to maintain the red color and delay the lipid oxidation of fresh beef kept under modified atmosphere.
Session 30C, Muscle Foods: Tenderness, Quality, Processing, Marination, Oxidation, and Shelf-Life
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